Why does Stitcher stop playback after the lock screen activates?

When
Power Saving Mode is active and Stitcher is playing directly from the network, playback may stop soon after the lock screen activates.

This is a feature of the Android operating system intended to help reduce excessive power consumption by preventing unwanted network communication. It affects all applications and is not specific to Stitcher.

Unfortunately, the feature ignores Stitcher's request to maintain network connectivity during playback. Stitcher is therefore unable to prevent this adverse interaction
but you can with the following device configuration change:

Navigate to the Battery section of the device's Settings panel.

Select the Power Saving Mode item (not the Ultra Power Saving Mode item).

Slide the Power Saving Mode toggle to the OFF position.

If your device is running Android OS 6.0 or later, there may be an additional popup menu in the
Battery panel to
Optimize Battery Usage per application rather than for all apps at once. This allows you to keep the feature enabled for most applications by identifying the specific applications which are allowed to access the network when Power Saving Mode activates.

Just add Stitcher to the
non-optimized apps list to prevent playback problems.